Abstract
V6O13 is a promising Li-ion battery cathode material for use in the high temperature oil field environment. The material exhibits a high capacity, and the voltage profile contains several plateaus associated with a series of complex structural transformations, which are not fully understood. The underlying mechanisms are central to understanding and improving the performance of V6O13-based rechargeable batteries. In this study, we present in situ X-ray diffraction data that highlight an asymmetric six-step discharge and five-step charge process, due to a phase that is only formed on discharge. The LixV6O13 unit cell expands sequentially in c, b, and a directions during discharge and reversibly contracts back during charge. The process is associated with change of Li ion positions as well as charge ordering in LixV6O13. Density functional theory calculations give further insight into the electronic structures and preferred Li positions in the different structures formed upon cycling, particularly at high lithium contents, where no prior structural data are available. The results shed light into the high specific capacity of V6O13 and are likely to aid in the development of this material for use as a cathode for secondary lithium batteries.
| Original language | English |
|---|---|
| Pages (from-to) | 5513-5524 |
| Number of pages | 12 |
| Journal | Chemistry of Materials |
| Volume | 29 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - 5 Jun 2017 |
Bibliographical note
Publisher Copyright:© 2017 American Chemical Society.
Acknowledgement:
We gratefully acknowledge the support given by Dr. Sylvia Britto, Kent J. Griffith (both University of Cambridge, U.K.), and Dr. Hao Liu (now Advanced Photon Source, U.S.). We especially thank Schlumberger Gould Research, Cambridge, U.K., for their financial support of this project via a studentship for W.M., and Dr. Nathan Lawrence and Dr. Tim Jones (from Schlumberger) for fruitful discussions. We also thank Dr. Tao Liu (University of Cambridge, U.K.) and Dr. Wanjing Yu (now Central South University, China) for their help with the SEM, Dr. Olaf J. Borkiewicz and Dr. Peter J. Chupas (both Advanced Photon Source, U.S.) for their help with the AMPIX cell. W.M. is also grateful to Cambridge Overseas Trust for funding this research project. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. P.M.B. gratefully acknowledges support from a FP7Marie Curie International Incoming Fellowship. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement numbers 655444 (O.P.) and 659764 (M.W.G.). R.P. acknowledges financial support from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement n. 317127 via our membership of the U.K.’s HPC Materials Chemistry Consortium, which is funded by EPSRC (n. EP/L000202). This work made use of the U.K.’s national high-performance computing service (ARCHER). Computational research was also carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract no. DE-AC0298CH10886.